System and Method for Operating Multiple Valves

Abstract

A valve system for providing fluid flow through radial openings disposed along an axial length of a tubular. The tubular comprises at least one valve group containing at least two valves operable by one drop ball. An inset 302 e.g. of standard grade steel provided in a harder liner 301 in the opening provides an intermediate small opening for at least the time required to open all the remaining valves in the group. The small opening limits the pressure drop over the valve. When all valves are open, the insets 302 are eroded away by an abrasive material, e.g. a slurry used for hydraulic fracturing, and permanent full openings are created.

1 . A valve system for providing fluid flow through radial openings disposed along an axial length of a tubular, comprising at least one valve group containing at least two valves operable by one drop ball, each valve having a closed state, an intermediate state providing an intermediate opening for at least the time required to open all the remaining valves in the group, and an open state providing a full radial opening larger than the intermediate opening. 
     
     
         2 . The valve system of  claim 1 , further comprising at least one valve operable to close fluid flow through the tubular. 
     
     
         3 . The valve system of  claim 1 , wherein each valve in a valve group comprises an expandable ball seat having a seat diameter adapted to the drop ball. 
     
     
         4 . The valve system of  claim 1 , wherein the intermediate opening is provided by an inset fit into the full radial opening. 
     
     
         5 . The valve system of  claim 4 , wherein the full radial opening is lined with a material that is harder than the inset. 
     
     
         6 . A method for providing fluid flow through radial openings disposed along an axial length of a tubular, comprising
 disposing at least one valve group associated with a section of the tubular, the valve group containing at least two valves operable by one drop ball in the tubular, each valve having a closed state, an intermediate state providing an intermediate opening for at least the time required to open all the remaining valves in the group, and an open state providing a full radial opening larger than the intermediate opening,   altering the state of each valve from the closed state to the intermediate state in turn using the drop ball, and   altering the state of each valve from the intermediate to the open state.   
     
     
         7 . The method of  claim 6 , wherein altering the state of each valve from the intermediate to the open state involves pumping an abrasive material through the openings. 
     
     
         8 . The method of  claim 6 , wherein more than one drop ball are used, each altering the valves in the valve group from their closed to their intermediate states. 
     
     
         9 . The method of  claim 6 , further comprising
 monitoring the fluid flowing through each valve section, and   closing the section of tubular associated with a valve section when the fluid flowing through it no longer satisfies predetermined criteria.   
     
     
         10 . The valve system of  claim 2 , wherein each valve in a valve group comprises an expandable ball seat having a seat diameter adapted to the drop ball. 
     
     
         11 . The method of  claim 7 , wherein more than one drop ball are used, each altering the valves in the valve group from their closed to their intermediate states. 
     
     
         12 . The method of  claim 7 , further comprising
 monitoring the fluid flowing through each valve section, and   closing the section of tubular associated with a valve section when the fluid flowing through it no longer satisfies predetermined criteria.   
     
     
         13 . The method of  claim 8 , further comprising
 monitoring the fluid flowing through each valve section, and   closing the section of tubular associated with a valve section when the fluid flowing through it no longer satisfies predetermined criteria.